查询词典 instantaneous power

PART 1 Electrical and Electronic Engineering Basics UNIT 1 A UNIT 2 A UNIT 3 A UNIT 4 A UNIT 5 A UNIT 6 A UNIT 7 A Electrical Networks ———————————— 3 B Three-phase Circuits The Operational Amplifier ——————————— 5 Logical Variables and Flip-flop —————————— 8 Power Semiconductor Devices —————————— 11 Types of DC Motors —————————————15 AC Machines ———————————————19 Electric Power System ————————————22 B Transistors B Binary Number System B Power Electronic Converters B Closed-loop Control of DC Drivers B Induction Motor Drive B Power System Automation PART 2 Control Theory UNIT 1 A B UNIT 2 A UNIT 3 A UNIT 4 A The World of Control ————————————27 Stability and the Time Response ————————— 30 The Root Locus ————————————— 32 The Transfer Function and the Laplace Transformation —————29 B Steady State————————————————— 31 B The Frequency Response Methods: Nyquist Diagrams ————— 33 The Frequency Response Methods: Bode Piots ————— 34 B Nonlinear Control System 37 UNIT 5 A Introduction to Modern Control Theory B B B PART 3 B B B State Equations Optimum Control Systems Artificial Neural Network Computer Control Technology 42 43 44 Fundamentals of Computer and Networks The Applications of Computers 46 40 38 UNIT 6 A Controllability, Observability, and Stability UNIT 7 A Conventional and Intelligent Control UNIT 1 A Computer Structure and Function UNIT 2 A Interfaces to External Signals and Devices UNIT 3 A PLC Overview PACs for Industrial Control, the Future of Control 1 UNIT 4 A Fundamentals of Single-chip Microcomputer 49 B B PART 4 B B B B PART 5 B B B B PART 6 Understanding DSP and Its Uses Embedded Systems Design Process Control 50 52 53 Fundamentals of Process Control UNIT 5 A A First Look at Embedded Systems UNIT 1 A A Process Control System UNIT 2 A Sensors and Transmitters Final Control Elements and Controllers PID Controllers and Other Controllers Control Panels Control Based on Network and Information Evolution of Control System Architecture Stability of NCSs with Network-induced Delay Virtual Manufacturing—A Growing Trend in Automation Enterprise Resources Planning and Beyond Synthetic Applications of Automatic Technology UNIT 3 A P Controllers and PI Controllers UNIT 4 A Indicating Instruments UNIT 1 A Automation Networking Application Areas UNIT 2 A Fundamental Issues in Networked Control Systems UNIT 3 A Fundamentals of the Database System UNIT 4 A Concepts of Computer Integrated Manufacturing UNIT 1 A Recent Advances and Future Trends in Electrical Machine Drivers B B B System Evolution in Intelligent Buildings A General Introduction to Pattern Recognition Electric Vehicles UNIT 2 A Industrial Robot UNIT 3 A Renewable Energy 2 UNIT 1 A

电路 电路或电网络由以某种方式连接的电阻器，电感器和电容器等元件组成。如果网络不包含能源，如电池或发电机，那么就被称作无源网络。换句话说，如果存在一个或多个能源，那么组合的结果为有源网络。在研究电网络的特性时，我们感兴趣的是确定电路中的电压和电流。因为网络由无源电路元件组成，所以必须首先定义这些元件的电特性。就电阻来说，电压-电流的关系由欧姆定律给出，欧姆定律指出：电阻两端的电压等于电阻上流过的电流乘以电阻值。在数学上表达为： u=iR (1-1A-1)式中 u=电压，伏特；i =电流，安培；R =电阻，欧姆。纯电感电压由法拉第定律定义，法拉第定律指出：电感两端的电压正比于流过电感的电流随时间的变化率。因此可得到：U=Ldi/dt 式中 di/dt =电流变化率，安培/秒； L =感应系数，享利。电容两端建立的电压正比于电容两极板上积累的电荷 q 。因为电荷的积累可表示为电荷增量 dq 的和或积分，因此得到的等式为 u=，式中电容量 C 是与电压和电荷相关的比例常数。由定义可知，电流等于电荷随时间的变化率，可表示为 i = dq/dt。因此电荷增量 dq 等于电流乘以相应的时间增量，或 dq = i dt，那么等式(1-1A-3)可写为式中 C =电容量，法拉。

ABSTRACT With the development of the ultra-high-voltage power systems and the power supply cables in cities, the charging imaginary power of the high-tension bus bar has become the key problem of the power systems.

随着超高压电网的发展和城市市区供电电缆的增加，高压线路上的充电无功功率已成为电网运行的主要问题之一。

The calculation of power factor is according to ratios of real power and total power. Lower power factor electric equipment representative have unnecessary busywork and harmonic components.

功率因数值的计算是根据实际消耗功率与视在消耗功率的比值为基准，因此功率因数不佳的电力设备即代表存在著不必要的虚功以及谐波成份。

Electronic equipment produces busywork and harmonic components that not only increase unnecessary loading and power consumption in public power equipment. But also harmonic components insert into public power system that causes deteriorating of power quality. Risks increase into break and mistake of precision instrument.

而电力设备所产生的虚功与谐波不仅无谓的加重公用电源设备的负担，增加无谓的功率消耗，更因为谐波成份的加入而使得电源品质恶化，增加精密设备损坏与误动作的风险。

Many people don't understand a truth. When the people could applaud the different ideas , he would not has a chickenshit mien but a wonderful mien ,not has a puny power but a strong power. When the people incarnate the autarchy and wildness, he would not has a great mien, but a droll mien, not has a strong power , but a narrow power.

很多人都不明白，当一个人可以听取不同意见时，他的形象是伟岸了而不是渺小了，他的力量是增强了，而不是削弱了；当一个人野蛮独裁的时候，他的形象是可笑了，而不是高大了，他的气势是狭隘了，而不是雄壮了。

Input power in the technical parmeters list is average power of the allowable power calculated from the antigluing capability of gear contact strength and the allowable power calculated from the antibending capability of the teeth of cogwheel of the turbine.

技术参数表中的"输入功率"；是按齿轮接触强度"抗胶合能力"计算的许用功率和按蜗轮轮齿"抗弯曲能力"计算的许用功率二者的平均功率。

In order to solve the application problem of conduction heating machining, this project investigates some problems, such as dynamic characteristics of heating power, features of circuit current and voltage, arc discharge states and so on. It also studies control characteristics of Uni-phase or Tri-phase Direct Current Power Supply and Inverse Switch Power Supply. A High Frequency Inverse Switch Commutate Power Supply is developed.

为了解决导电加热切削的应用问题，从加热电源的动态性能和回路的电流、电压特性及电弧放电状态等方面进行研究，分析比较了单、三相交直流电源和逆变开关电源的特点和控制特性，研制了高频逆变开关整流电源。

Theorem 1 If the power series is convergent at ,then for any that ,the power series absolutely converges at point ;if the power series is divergent at ,then for any that ,the power series diverges at point .

定理1 如果级数当时收敛，则适当不等式的一切使这幂级数绝对收敛；反之，如果级数当时发散，则适合不等式的一切使这幂级数发散。

And this paper assumes that resisting power is accordwith parabola, gets all arch as basic configuration, gets formulation from the condition that therelative corner , horizontal displacement and vertical displacement of vault section iszero,adds deformation condition of maximum resisting power and zero resisting power, solvesequation group to get the internal force of lining . And lining internal force computing methodunder bias load based on assumed resisting power method is formulized.

本文假定弹性抗力按二次抛物线分布，取全拱为基本结构，由拱顶截面的相对转角、相对水平位移和相对垂直位移为零的条件列出变形协调方程，再增加最大弹性抗力处的变形协调条件和弹性抗力为零处径向位移为零的变形协调条件，解方程组求解得出衬砌结构的弹性抗力分布及内力。

In Two-Transistor Flyback Converter circuit, a power semiconductor device in Flyback Converting circuit has been replaced by two power semiconductor devices which parallel connected with an ultra-fast diode with soft recovery characteristics. Two-Transistor Flyback Converter can reduce greatly the switching stress of the power switch and does not need to degausser, suitable for high input voltage Switching Power Supply.

反激变换是从Buck-Boost变换演变而来的，将反激变换电路中的单个功率开关管用两个替代，并在每个功率开关管上并联一十箝啦的快恢复二极管而形成的双晶体管反激变换电路，能大大降低功率开关管承受的开关应力，且不需要消磁电路，非常适用于高输入电压的开关电源。

Alternatively, the con- trollers can use the synchronous rectifier itself or loss- less inductor current-sensing methods to provide overload protection with lower power dissipation.

另外，康威特罗勒斯可以使用同步整流器本身或亏损减少电感电流检测方法，以提供低功耗过载保护。

Mr. Dauber's other Schatz hangs in his home movie studio.

多伯把沙兹的另一件作品挂在家里的电影室。